title: Ambient temperature and nutritional stress influence fatty acid composition of structural and fuel lipids in Japanese quail (Coturnix japonica) tissues.
abstract: In birds, fatty acids (FA) serve as the primary metabolic fuel during exercise and fasting, and their composition affects metabolic rate and thus energy requirements. To ascertain the relationship between FAs and metabolic rate, a distinction should be made between structural and fuel lipids. Indeed, increased unsaturation of structural lipid FAs brings about increased cell metabolism, and changes in the FA composition of fuel lipids affects metabolic rate through selective mobilization and increasing availability of specific FAs. We examined the effects of acclimation to a low ambient temperature (Ta: 12.7±3.0°C) and nutritional status (fed or unfed) on the FA composition of four tissues in Japanese quail, Coturnix japonica. Differentiating between neutral (triglycerides) and polar (phospholipids) lipids, we tested the hypothesis that both acclimation to low Ta and nutritional status modify FA composition of triglycerides and phospholipids. We found that both factors affect FA composition of triglycerides, but not the composition of phospholipids. We also found changes in liver triacylglyceride FA composition in the low-Ta acclimated quail, namely, the two FAs that differed, oleic acid (18:1) and arachidonic acid (20:4), were associated with thermoregulation. In addition, the FAs that changed with nutritional status were all reported to be involved in regulation of glucose metabolism, and thus we suggest that they also play a role in the response to fasting.
authors.affiliation: Albert Katz International School for Desert Studies, Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990 Midreshet Ben-Gurion, Israel. miriammi@bgu.ac.il
authors.forename: Miriam
authors.initials: M
authors.lastname: Ben-Hamo
authors.forename: Marshall D
authors.initials: MD
authors.lastname: McCue
authors.forename: Inna
authors.initials: I
authors.lastname: Khozin-Goldberg
authors.forename: Scott R
authors.initials: SR
authors.lastname: McWilliams
authors.forename: Berry
authors.initials: B
authors.lastname: Pinshow
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D003370:Coturnix / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D050356:Lipid Metabolism; D044342:Malnutrition / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D009928:Organ Specificity; D010743:Phospholipids / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D005227:Fatty Acids; D010743:Phospholipids
keywords: Bird; Fasting; Membranes; Metabolic rate; Nonpolar lipids; Phospholipids; Starvation; Triglycerides